I saw a couple things today which confused me.
The first was that Wolgraff, my Rogue, somehow failed to cast Fast Track on himself, despite having a 100%+ chance to caste it. He was under no status effects, and it did use the AP, Fast Track appeared in the combat log, but the Haste effect never happened. I don't know if it's related, but on the previous turn I had my Inquisitor cast Fast Track on herself. It worked. But I don't know why Wolgraff's failed when it by definition his > 100% success chance means it can't fail.
The second was that my Inquisitor had to retreat from a battle with the Fire Twins. She ran off, cast a healing spell on herself, and then cast Walk In Shadows (invisibility) on herself. Now, the invisibility had a stated duration of 5 turns. On the second turn, the healing happened, and she remained invisible. On the third turn, she, for NO REASON AT ALL, became visible. No reason. She wasn't hit by anything. What the hell?
Invisibility in combat already has enough stupid problems that it doesn't need completely random decloaking added to it. It is a terrible idea that status effects that you had before casting invisibility (burning, poison) can decloak you, because you tend to use combat invisibility because you really want to run away and heal, and it really sucks to get decloaked by poisoning.